Nicholas has broken this out into multiple packages, and is actively updating only those. Here is the theme. See: https://github.com/rougier/nano-theme
Seems like a poor naming choice as Nano is already a common text editor
Thought it will change keybindings to be closer to nano's.
The mu4e front end looks really nice. I’ve ne er wanted to use Emacs as a mail client but this could worth a try